To me diet is a lifestyle issue. Your daily routine will determine a great many of the factors of what you eat.
What is available to you, where you are, how much time you have, what foods you were raised on, your chemical and biological makeup, are only a few of the considerations. For all of us there is an emotional aspect of eating. How much effort are you willing to put into changing your eating habits. All of these factors and more constitute your particular and unique lifestyle. Married, single, children, all matter.
A diet that is going to require you to pack a lunch in order to meet its numbers is just not going to cut it for a great number of people. I have found what is most effective in the long run are for my clients to keep a detailed log of everything they eat over a three-week period. I will then have them replace one item with something healthy. Only when they have assimilated that change into their eating habits do I make another similar change. I call this the Quality phase in which I clean up their eating habits. In the vast majority of my clients who actually get to a clean diet the results exceed their wildest dreams. Almost all reach their goals along the way.
For the few who can over eat a clean healthy diet I then start reducing the amount of food they consume by very small amounts allowing them to adjust to the decreases so as not to impact their lifestyle emotionally. This is my Quantity phase. This way my clients do not have to make radical or abrupt changes in their lifestyle to accommodate the changes in their eating habits.